Analysis of the dynamic response of a ring resonator to a time-varying input signal

1993 ◽  
Vol 18 (6) ◽  
pp. 465 ◽  
Author(s):  
K. Kalli ◽  
D. A. Jackson
Keyword(s):  
Dynamic Response ◽  
Input Signal ◽  
Ring Resonator ◽  
Time Varying

Vibration-based fault diagnosis of helical gear pair with tooth surface wear considering time-varying friction coefficient under mixed EHL condition

2021 ◽  
pp. 1-16
Author(s):  
Siyu Wang ◽  
Rupeng Zhu
Keyword(s):  
Dynamic Response ◽  
Hydrodynamic Lubrication ◽  
Helical Gear ◽  
Calculation Model ◽  
Tooth Surface ◽  
Time Varying ◽  
Gear Pair ◽  
Surface Wear ◽  
Mesh Stiffness ◽  
Helical Gear Pair

Abstract Based on “slice method”, the improved time-varying mesh stiffness (TVMS) calculation model of helical gear pair with tooth surface wear is proposed, in which the effect of friction force that obtained under mixed elasto-hydrodynamic lubrication (EHL) is considered in the model. Based on the improved TVMS calculation model, the dynamic model of helical gear system is established, then the influence of tooth wear parameters on the dynamic response is studied. The results illustrate that the varying reduction extents of mesh stiffness along tooth profile under tooth surface wear, in addition, the dynamic response in time-domain and frequency-domain present significant decline in amplitude under deteriorating wear condition.

Non-Linear Modal Interactions in a Suspension Rope System with Time-Varying Length

2006 ◽  
Vol 5-6 ◽  
pp. 217-224 ◽  
Author(s):  
Rodanthi Salamaliki-Simpson ◽  
Stefan Kaczmarczyk ◽  
Phil Picton ◽  
Scott Turner
Keyword(s):  
Dynamic Response ◽  
Equations Of Motion ◽  
Time Varying ◽  
Modal Interaction ◽  
Modal Interactions ◽  
Autoparametric Resonance ◽  
Non Linear ◽  
Varying Length ◽  
Host Structure ◽  
Rope System

This paper focuses on the investigation of the autoparametric coupling effects and modal interactions in a suspension rope system with a time varying length. Equations of motion of a multi-degree-of-freedom discrete, non-stationary and non-linear model are presented and are used to analyze the dynamic response of an elevator suspension rope system under resonance conditions. The equations of motion involve quadratic and cubic non-linear terms which are responsible for the modal interaction between the lateral and longitudinal oscillations of the rope and the car motions. The model takes into account the periodic excitations caused by motion of the host structure. The results confirm that adverse responses may arise and internal autoparametric resonance phenomena may occur.

Intracranial pressure waves: characterization of a pulsation absorber with notch filter properties using systems analysis

2008 ◽  
Vol 2 (1) ◽  
pp. 83-94 ◽  
Author(s):  
Rui Zou ◽  
Eun-Hyoung Park ◽  
Erin McCormack Kelly ◽  
Michael Egnor ◽  
Mark E. Wagshul ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cerebrospinal Fluid ◽  
Intracranial Pressure ◽  
Transfer Function ◽  
Input Signal ◽  
Systems Analysis ◽  
Notch Filter ◽  
Time Varying ◽  
Cardiac Frequency ◽  
Arterial Blood

Object The relationship between the waveform of intracranial pressure (ICP) and arterial blood pressure can be quantitatively characterized using a newly developed technique in systems analysis, the time-varying transfer function. This technique considers the arterial blood pressure as an input signal composed of multiple frequencies represented in the output ICP according to the transfer function imposed by the intracranial system on the input signal. The transfer function can change with time and with physiological manipulations. The authors examined data obtained from canine experiments involving manipulations of ICP. Methods The authors analyzed 11 experiments from 3 normal mongrel dogs under conditions of normal ICP and with changes in ICP made by bolus injection, infusion, or withdrawal of cerebrospinal fluid by using time-varying transfer function. Results During normal ICP periods, the gain of the transfer function displayed a deep notch (≥ 1 log unit) centered at or near the cardiac frequency. In systems terms, the intracranial compartment under normal conditions appears to act as a notch filter attenuating the cardiac frequency input relative to other frequencies. Epochs of ICP elevation showed suppression of the notch, and the notch was restored when ICP returned to normal. Conclusions The intracranial system in these animals could be considered to include a pulsation absorber for which the target frequency appears to be close to the cardiac frequency. One possible source for such an absorber mechanism might be the free movement of cerebrospinal fluid, implying that impairment of this motion may have important clinical implications in various neurological conditions such as hydrocephalus.

Effect of Negative Damping on Offshore Structures

2018 ◽  
Author(s):  
Gizat Derebe Amare ◽  
Yonas Zewdu Ayele
Keyword(s):  
Dynamic Response ◽  
Structural Design ◽  
Offshore Structures ◽  
Response Amplitude ◽  
Time Varying ◽  
Flow Induced Vibrations ◽  
Negative Damping ◽  
Wave Conditions ◽  
Short Time ◽  
Damping Model

Offshore structures are inevitably exposed to flow induced loads and flow-induced vibrations. The effect of these loads will affect the responses of structures, and the combined of two together on the response can lead the structures to induce different phenomena. The effect of damping is to counteract any dynamic response; however, “negative damping” increases the response amplitude. For example, the response amplitude may increase and can lead to structure instabilities, and it might cause damage in the short time. In order to achieve the best possible structural design, it is then relevant to study conditions under which structure instabilities occur. The purpose of this paper is to discuss the conditions under which offshore structures could induce “negative damping” and different structural phenomena that have been caused by “negative damping”. The discussion suggests a damping model with linear and time-varying terms, and shows theoretically that the model is negative under certain wave conditions.

scholarly journals Metaheuristic Regression Equations for Split-Ring Resonator Using Time-Varying Particle Swarm Optimization Algorithm

Electronics ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 300
Author(s):  
Muhammad Mughal ◽  
Tahir Ejaz ◽  
Arshad ◽  
Ashiq Hussain
Keyword(s):  
Particle Swarm Optimization ◽  
Resonant Frequency ◽  
Quality Factor ◽  
Ring Resonator ◽  
Particle Swarm ◽  
Split Ring Resonator ◽  
Regression Equations ◽  
Time Varying ◽  
Split Ring ◽  
Swarm Optimization

This article presents a new technique for determining accurate values of resonant frequency and quality factor pertaining to the split-ring resonator. Different conducting shield materials have been used around a copper split-ring. The split-ring has been designed to operate at about 2.1 GHz. Various equations were worked out earlier to determine the values of resonant frequency and quality factor. However, these equations yielded different solutions. Therefore, simulations were used to obtain the values of the resonant frequency and quality factor of the split-ring resonator with different five-shield materials, using High-Frequency Structure Simulator (HFSS) software. In this work, a novel method has been introduced for obtaining values of resonant frequency which provides results with negligible error. An optimal technique, namely time-varying particle swarm optimization (TVPSO), was then performed to obtain two sets of equations for resonant frequency and quality factor. The two sets of equations, optimized using TVPSO, were compared for their effectiveness in matching the actual frequency and quality factor for each of the five materials. It was found that the TVPSO was significant in achieving the frequency and quality factor regression equation to accurately resemble the actual values portrayed by the low mean absolute error.

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